Detergent composition having softening properties

ABSTRACT

Simultaneous cleansing and softening of fabrics is achieved by use of an aqueous solution of a mixture of synthetic organic noncationic detergent and an alkali metal salt of isostearic acid as the fabric wash water.

United States Patent Inventor Marvin C. Weast Anaheim, Calif.

Appl. No. 684,959

Filed Nov. 22, 1967 Patented Dec. 7, 1971 Assignee Purex Corporation,Ltd.

Lakewood, Calil.

DETERGENT COMPOSITION HAVING SOFTENING PROPERTIES 19 Claims, No DrawingsU.S. Cl 252/109, 252/8.7, 252/121, 252/138, 252/161 lnt.Cl Clld 9/10, Cl1d 3/065 Field of Search 252/ 1 2 l 8.6, 8.7, 138, 109; 8/137, 142

References Cited UNITED STATES PATENTS 7/1969 Clark et al. 252/8.8

2,567,645 9/1951 Limburg 252/121 2,954,347 9/1960 St. John et a1.252/109 2,527,329 10/1950 Powers et'al 117/1395 FOREIGN PATENTS 348,7835/1931 Great Britain 252/8.6 640,373 7/1950 Great Britain.... 252/109303,379 12/1928 Great Britain.... 252/8.6 431,964 7/1935 GreatBritain... 252/8.6 737,824 10/1955 Great Britain 252/109 OTHERREFERENCES Marsh, J. T., An Introduction to Textile Finishing, 2dEdition, pp. 259- 266, Chapman & Hall Ltd., London 1948.

Primary Examiner- Leon D. Rosdol Assistant Examiner-P. E. WillisAttorney-White and Haefliger 7 salt of isostearic acid as the fabricwash water.

DETERGENT COMPOSITION HAVING SOFTENING PROPERTIES BACKGROUND OF THEINVENTION Field Of The Invention Synthetic organic detergents have foundwidespread use as cleaning materials for fabrics of all fibers. Numerousof these materials, including the most popular so-called heavy duty"detergents, which typically consist of an alkyl benzene sulfonate and awater soluble inorganic builder salt such a sodium tripolyphosphate, inaqueous wash solutions lend to fabrics a roughness or lack of hand"which is commercially disadvantageous.

It has been proposed to add after washing, with the final rinse, asoftening agent such as l-methyl-1-alkylamidoethyl-2- alkylimidazoliniummethosulfate. Since few automatic washing machines provide for automatedintroduction of this material, the housewife must stand by her automaticwasher to add this softener product at the onset of the final rinsecycle. Toleration of this inconvenience merely illustrates the concernshown by consumers today for softness in washed fabrics.

SUMMARY OF THE INVENTION It is a major objective of the presentinvention to obviate critical sequential addition of laundry productswith their attendant time waste and possible improper execution. Inaddition, it is an object to provide a single package laundry productwhich both washes and softens, in the same wash water, by a singleaddition. It is a further object to provide a softening productpackageable with synthetic organic detergent and substantive to fabricthrough a detergent washing operation.

It has now been discovered that softening characteristics may beimparted to synthetic organic detergents by intimately mixing therewitha C saturated fatty acid or a water soluble salt thereof having a methylsubstituted tertiary atom. The intimate mixing may be accomplished by acodissolving the detergent and acid or salt in water and removing thewater, e.g. in a conventional detergent spray drying apparatus.

There results from this preparation a detergent and fabric softeningcomposition which consists essentially of a mixture of noncationicsynthetic organic detergent and the aforedescribed fatty acid or salt.Commercially available C acids may be employed including those in whichthere may be present up to 60 weight percent acids or salts other thanmethyl branched C e.g. C to C saturated fatty acids or their salts. Forexample, a commercial saturated fatty acid of the formula C, H ,COOHcomprising a complex mixture of isomers, primarily of the methylbranched series that are mutually soluble and only difficulty separablemay be used. The term C acid (or salt) is used herein to include suchmixtures. Anionic detergents are preferred herein, particularly alkylsulfate and alkyl sulfonate anionic detergents such as alkali metaltallow alcohol sulfates and dodecyl benzene sulfonates e.g. sodium saltsof the corresponding acids, and mixtures of these detergents.Proportions are not particularly critical with weight ratios ofdetergent to acid in the range of l:l to 0.5:l being suitable. Additivesconventional in detergent formulation including, by way of illustration,builder salts, perfumes, optical brighteners, binders, et cetera, mayalso be employed.

The invention thus provides a method of softening fabrics during washingthereof with an aqueous washing solution of a synthetic organicdetergent which includes introducing in the washing solution a Csaturated fatty acid or water-soluble salt thereof having a methylsubstituted tertiary carbon atom.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The essential components of thepresent inventive compositions are the synthetic organic detergent andthe methyl branched C fatty acid or salt.

With respect to the sythetic organic detergent, useful materials are thenonionic, amphoteric or anionic i.e. noncationic detergents.

In general, suitable nonionic detergents include water-soluble nonionicpolyalkylene oxide detergents such as are produced by the introductionof alkylene oxide group into an organic hydrophobic compound or grouphaving an aliphtic or aromatic structure. The hydrophobic organic groupgenerally contains at least eight carbon atoms and up to about 30 carbonatoms. Condensed with the hydrophobic group are at least five andpreferably up to about 50 alkylene oxide groups. It is preferred to usethe polyoxyethylene condensates derived from ethylene oxide. Among thenonionic detergents, it is preferred to use the polyalkylene oxidecondensates of alkyl phenol, such as the polyoxyethylene ethers of alkylphenols having a alkyl group of at least about six, and usually abouteight to 12 carbons, and an ethylene oxide ratio (No. of moles perphenol) of about 7.5, 8.5, 1 1.5 and 20, through the number of ethyleneoxide groups will be usually from about eight to 18. The alkylsubstituent on the aromatic nucleus may be diisobutylene, diamyl,polymerized propylene, dimerized C -C olefin, and the like.

Further suitable detergents are the polyoxyalkylene esters of organicacids, such as the higher fatty acids, rosin acids, tall oil acids, oracids from the oxidation of petroleum, et cetera. These polyglycolesters will contain usually from about 12 to about 30 moles of ethyleneoxide or its equivalent and about eight to 22 carbons in the acyl group.Suitable products are refined tall oil condensed with 16 or 20 ethyleneoxide groups, or similar polyglycol esters of lauric, stearic, oleicacids, etc.

Additional nonionic agents are the polyalkylene oxide condensates withhigher fatty acid amides, such as the higher fatty acid primary amides,monoand di-ethanolamides. Suitable agents are coconut fatty acid amidecondensed with about 10 to 50 moles of ethylene oxide. The fatty acylgroup will have similarly about eight to 22 carbons, and usually aboutl0-to 18 carbon atoms, in such products. The corresponding sulfonamidesmay be used also if desired.

Other suitable polyether nonionic detergents are the polyalkylene oxideethers of higher aliphatic alcohols. Suitable fatty alcohols having ahydrophobic character, preferably eight to 22 carbons, are lauryl,myristyl, cetyl, stearyl and oleyl alcohols which may be condensed withan appropriate amount of ethylene oxide, such as at least about 6, andpreferably about [0 to 30 moles. A typical product is oleyl alcoholcondensed with about l2, 15 or 20 moles of ethylene oxide. Thecorresponding higher alkyl mercaptans or thioalcohols condensed withethylene oxide are suitable in the present invention also. Thewater-soluble polyoxyethylene condensates with hydrophobicpolyoxypropylene glycols may be employed also.

Further suitable nonionic detersive materials are the higher fatty acidalkanolamides, such as the monoethanolamides, diethanolamides andisopropanolamides wherein the acyl radical has about 10 to 14 carbonatoms and amine oxides. Examples are coconut (or equivalent lauric),capric and myristic diethanolamide, monoethanolamide andisopropanolamide, dodecyl dimethyl amine oxide and dimethylacetoxyalkylamine oxide where alkyl is C,,-C,,,.

Other suitable synthetic detergents are the anionic aromatic detergents,e.g. water-soluble higher alkyl aryl sulfonate detergents particularlythose having from eight to about l8 carbon atoms in the alkyl group. Itis preferred to use the higher alkyl benzene sulfonate detergent foroptimum effects, though larly those having about eight to 18 carbons inthe fatty alcohol residue, such as lauryl (or coconut fatty alcohol)sulfate and tallow alcohol sulfate. Other suitable detergents are thesulfuric acid esters of polyhydric alcohols incompletely esterified withhigher fatty acids, e.g. oleic acid ester of isothionic acid; the higherfatty acid (e.g. cocanut ethanolamide sulfate, the higher fatty acidamide of amino alkyl sulfonic acids, e.g. lauric acid amide of taurine;and the like.

These sulfate and sulfonate detergents are used in the form of theirwater-soluble salts, such as the alkali metal and nitrogen-containing,e.g. lower alkylolamine, salts. Examples are the sodium, potassium,ammonium, isopropanolamine, monoand tri-ethanolamine salts of saidhigher alkyl benzene sulfonate, higher alkyl sulfate and the like. Incommercial practice, it is preferred to use the alkali metal salts.

Typical specific examples are:

the sodium salt of a sulfate ester of an alkylphenoxypoly (ethyleneoxy)ethanol, the ammonium salt of this sulfate ester, sodium methyl oleyltaurate, sodium alkyl naphthalene sulfonate, alkyl acyl sodiumsulfonate, sodium tetrahydronaphthalene sulfonate, sodium alkyl arylsulfonate, alkyl amido sulfate, cocomonoglyceride sulfate,dodecylbenzene sodium sulfonate, dodecylbenzene sulfonic acid,tridecylbenzene sodium sulfonate, fatty alcohol sodium sulfate, sodiumdodecyl diphenyl oxide disulfonate, sulfonated castor oil,polyethoxyalkyl phenol sulfonate triethanolamine salt, sodiumtn'ethanolamine alkyl aryl sulfonate, magnesium lauryl sulfate,potassium lauryl sulfate, sodium lauryl ether sulfate, ammonium laurylether sulfate, sodium tallow sulfate, dodecylbenzene sodium sulfonate,oleyl methyl tauride, ammonium lauryl sulfate, amide sulfonate, and thelike.

Other noncationic materials such as amphoteric detergent materials canbe employed in formulations having a pH above the materials isoelectricpoint including, illustratively, the sodium salt of N-coco beta aminopropionate, N-lauryl beta amine propionic acid and metal salts ofsubstituted quaternary hydroxy cycloimidinic acid metal alcoholates suchas disclosed in USP 2,528,378 to Mannheimer.

The softeners herein found to be substantive to fabric through adetergent wash cycle and applicable during such cycle are generally theC saturated fatty acids and their water-soluble salts in which thereoccurs a methyl substituted tertiary carbon atom, in other words C fattyacids free of aliphatic unsaturation and having a branch chain. Suchacids have the formula:

1 Me in which R is a divalentorganic radical of l7 carbon atoms and Meis a methyl side chain located on any but the terminal carbon atom of R,which substituted carbon atom is thus a tertiary carbon atom.

Branch chain stearic acids having along the chain a methyl group sidechain often termed isostearic acids" in the trade. The methyl groupposition generally will vary with the acid source, particularly if anatural product e.g. degras or sheep wool fat. Typical values forcommercially available isostearic acids are:

Molecular weight 284 Viscosity cps at 25C. 48 Acid Value l75 Titer C. 10Iodine value ID The water-soluble salts of these acids may be used inaddition to win place of all or part of the acid. In general, suitablesalts are the alkali metal salts e.g. of the formula:

II Me R -c OOM derived from alkyl amines and alkanolamines e.g. fromprimary, secondary and tertiary alkyl amines such as mono-, di-, ortri-methyl, ethyl, propyl or butyl amines or primary, secondary andtertiary alkanol amines such as mono-, di-, or trimethanol, ethanol,propanol and isopropanol amines.

Proportions of synthetic organic detergent and C particular fatty acidor salt are not narrowly critical with as little as 0.5 part of thedetergent per pan of the fatty acid/salt or 10 parts of detergent and 1part of the acid/salt, by weight, being broadly useful in providingvarying ranges of cleaning and softening action. in commercialformulations the weight ratio of synthetic organic detergent to fattyacid/salt will generally range between 5:1 and 1:1 with between 4:1 and2:1 and especially the latter being particularly preferred when themixture is blended with builder salts, as described below.

Builder salts are materials added to detergent formulations to assist insoil dispersion or suspension, deflocculation and water softening and toincrease the alkalinity of the system. While suitable water-solubleinorganic salt may be employed commercially used materials are thealkali metal salts e.g. sodium, pottassium, lithium and cesium metalsalts of phosphoric, sulfuric, carbonic or silicic acids. Typicalmaterials include trisodium phosphate, tetrasodium phosphate, sodiumtripolyphosphate, sodium sulfate, sodium carbonate, sodium silicate,potassium sulfate, phosphates, carbonates and silicates.

Builder salts are employed in conventional amounts, e. g. 4: l to 1:1 byweight relative to the detergent, with weight ratios of 2:1 to 3:l beingpreferred.

in the preparation of a typical formulation; a crutcher is charged withl sodium tallow alcohol sulfate, 10-20 percent by weight of the whole;(2) sodium tripolyphosphate, sodium sulfate, sodium silicate, (20-60percent); (3) carboxymethylcellulose; (4) isostearic acid (-l0 percent);(5) sodium hydroxide (to neutralize the isostearic acid); brightenersand water to form a slurry of 50 percent solids.

The aqueous slurry is heated above F. and crutched until lump-free. Theslurry is then deaerated and spray-dried so that the resulting, easilydissolved, detergent beads have 5-10 percent moisture.

in the examples all parts are by weight.

EXAMPLE 1 The following were blended and formed into detergent beads asabove described:

Tallow Alcohol Sulfate 20 parts Sodium Tripolyphosphate 40 parts Sodiumlsostearate 10 parts Sodium Sulfate l3.5 parts CarboxymethylCellulose 1. parts Optical Brighteners 0.5 parts Sodium Silicate 5.0parts Water 10.0 parts l00.0 parts The isostearic acid used was acommercial grade known as Emery 3l0l-D lsostearic Acid containing aminimum of 40 percent by weight C acids.

FABRIC WASHING PROCEDURE Fabric softening was tested by using terrycloths placed in a home-type automatic washing machine along with a loadof naturally soiled fabrics. One cup of the spray-dried composition wasadded to the 15 gallon washer and set through the normal wash, rinse andspin-dry cycles. The wash load, including the test cloths, was dried ina home-type drier.

CONTROL 1 For comparison, an identical load was washed using the leadingdetergent powder.

The two sets of coded cloths were evaluated by a panel of 10 persons whoranked the cloths according to softness. This procedure was repeated for10 cycles. Using statistical optical methods, it was determined that thecloths washed in detergents with isostearic acid were significantlysofter (at the 95 percent confidence level) than the cloths washed inthe commercially-available detergent powder. The difference was notedfrom the first wash cycle through the th.

Other illustrative formulations include:

EXAMPLE 2 Sodium Tallow Alcohol Sulfate 20 parts Sodium tripolyphosphate40 parts Sodium lsostearate 8-12 parts Sodium sulfate lS.S-l 1.5 pansCarboxymclhyl cellulose l.0 parts Optical Brighteners 0.5 parts Sodiumsilicate 5.0 parts Water 10.0 parts l00.0 parts EXAMPLE 3 Sodium TallowAlcohol Sulfate 20 pans Sodium Tripolyphosphate 40 parts Potassiumlsostearate 2 parts Sodium Sulfate 21.5 parts Carboxy methyl cellulosel. parts Optical Brighteners 0.5 parts Sodium Silicate 5.0 parts Waterl0.0 parts l00.0 parts EXAMPLE 4 Sodium Tallow Alcohol Sulfate 20 partsSodium Tripolyphosphate 40 parts Sodium lsostearate 20 parts SodiumSulfate 3.5 parts Carboxy methyl cellulose 1. parts Optical Brighteners0.5 parts Sodium Silicate 5.0 parts Water 10.0 parts l00.0 pans EXAMPLE5 Sodium Dodecylbenzene sulfonute (anionic detergent) 67 parts Sodiumlsostearute 33 parts EXAMPLE 6 Nonyl phenoxy polyethoxy ethane(non-ionic detergent) 67 pans Sodium lsostearatc 33 parts CONTROL llExample 1 is duplicated using normal stearic acid. No statisticallysignificant improvement over the control I is noted.

The foregoing softening additive acids and salts may be blended withamine treated clays to enchance or compliment the fabric softeningaction.

lclaim:

1. Method of preparing compositions for imparting fabric softeningcharacteristics to water soluble anionic, nonionic and amphotericsynthetic organic detergents which includes intimately mixing thedetergent with an alkali metal salt of isotearic acid in a weight ratioof 0.5:l to 10:1 of detergent to said isostearic acid salt bycodissolving the detergent and salt in water and removing the water fromthe mixture by heating.

2. Method according to claim 1 in which the water is removed by spraydrying the solution.

3. Detergent composition having both fabric cleaning and softeningcharacteristics, which consists essentially of a mixture of a detergentselected from the group consisting of water soluble anionic, nonionicand amphoteric synthetic organic detergents and an alkali metal salt ofisostearic acid in a weight ratio of 0.5:1 to 10:] of detergent to saidsalt.

4. Detergent composition according to claim 3 in which said salt is analkali metal salt selected from lithium, sodium and selected from thegroup consisting of potassium salts.

5. Detergent composition according to claim 4 in which said salt is thesodium salt.

6. Detergent composition according to claim 3 including also C to Csaturated fatty acids except C fatty acids in up to 60 weight percent ofthe total of fatty acids present in the composition.

7. Detergent composition according to claim 3 in which said detergent isan anionic detergent.

8. Detergent composition according to claim 7 in which said anionicdetergent is an alkyl aryl sulfonate detergent in which the alkyl groupcontains from eight to 22 carbon atoms.

9. Detergent composition according to claim 8 in which said anionicdetergent is alkyl benzene sulfonate.

l0. Detergent composition according to claim 7 in which said anionicdetergent is an alkyl sulfate in which the alkyl group contains fromeight to 22 carbon atoms.

11. Detergent composition according to claim 10 in which said anionicdetergent is tallow alcohol sulfate.

12. Detergent composition according to claim 3 in which said detergentis nonionic.

13. Detergent composition according to claim 3 in which said detergentincludes both an alkyl sulfate and an alkyl aryl sulfonate detergent inwhich the alkyl groups each contain from eight to 22 carbon atoms.

14. Detergent composition according to claim 13 in which said alkylsulfate is tallow alcohol sulfate and said alkyl aryl sulfonate isdodecyl benzene sulfonate.

15. Detergent composition according to claim 3 in which the weight ratioof said detergent to said salt is from S: l to l l l6. Detergentcomposition according to claim 15 in which said detergent is a mixtureof alkyl sulfate and alkyl aryl sulfonate detergents in which said alkylgroups each contain from eight to 18 carbon atoms and in proportions of4:1 to 2:l by weight.

17. Detergent composition according to claim 3 in which there isadditionally present from 20 to 60 percent by weight of a water-solubleinorganic builder salt in the total composition.

18. Method of softening fabrics during washing thereof with an aqueouswashing solution of a synthetic organic noncationic detergent whichincludes introducing into the washing solution an alkali metal salt ofisostearic acid in a weight ratio of 0.5:l to 10:] of detergent to saidsalt.

19. Method according to claim 18 in which the weight ratio of detergentto isostearic acid salt in said solution is between 5:1 and 1:1.

2. Method according to claim 1 in which the water is removed by spraydrying the solution.
 3. Detergent composition having both fabriccleaning and softening characteristics, which consists essentially of amixture of a detergent selected from the group consisting of watersoluble anionic, nonionic and amphoteric synthetic organic detergentsand an alkali metal salt of isostearic acid in a weight ratio of 0.5:1to 10:1 of detergent to said salt.
 4. Detergent composition according toclaim 3 in which said salt is an alkali metal salt selected from thegroup consisting of lithium, sodium and potassium salts.
 5. Detergentcomposition according to claim 4 in which said salt is the sodium salt.6. Detergent composition according to claim 3 including also C14 to C22saturated fatty acids except C18 fatty acids in up to 60 weight percentof the total of fatty acids present in the composition.
 7. Detergentcomposition according to claim 3 in which said detergent is an anionicdetergent.
 8. Detergent composition according to claim 7 in which saidanionic detergent is an alkyl aryl sulfonate detergent in which thealkyl group contains from eight to 22 carbon atoms.
 9. Detergentcomposition according to claim 8 in which said anionic detergent isalkyl benzene sulfonate.
 10. Detergent composition according to claim 7in which said anionic detergent is an alkyl sulfate in which the alkylgroup contains from eight to 22 carbon atoms.
 11. Detergent compositionaccording to claim 10 in which said anionic detergent is tallow alcoholsulfate.
 12. Detergent composition according to claim 3 in which saiddetergent is nonionic.
 13. Detergent composition according to claim 3 inwhich said detergent includes both an alkyl sulfate and an alkyl arylsulfonate detergent in which the alkyl groups each contain from eight to22 carbon atoms.
 14. Detergent composition according to claim 13 inwhich said alkyl sulfate is tallow alcohol sulfate and said alkyl arylsulfonate is dodecyl benzene sulfonate.
 15. Detergent compositionaccording to claim 3 in which the weight ratio of said detergent to saidsalt is from 5:1 to 1:1.
 16. Detergent composition according to claim 15in which said detergent is a mixture of alkyl sulfate and alkyl arylsulfonate detergents in which said alkyl groups each contain from eightto 18 carbon atoms and in proportions of 4:1 to 2:1 by weight. 17.Detergent composition according to claim 3 in which there isadditionally present from 20 to 60 percent by weight of a water-solubleinorganic builder salt in the total composition.
 18. Method of softeningfabrics during washing thereof with an aqueous washing solution of asynthetic organic noncationic detergent which includes introducing intothe washing solution an alkali metal salt of isostearic acid in a weightratio of 0.5:1 to 10:1 of detergent to said salt.
 19. Method accordingto claim 18 in which the weight ratio of detergent to isostearic acidsalt in said solution is between 5:1 and 1:1.